Abstract

A quantitative method of externally evaluating nutritional myocardial capillary supply has long been sought. An idealized testing procedure should monitor capillary blood supply as well as transcapillary exchange without disrupting the normal physiologic status. Such a determination can now be accomplished by using a double coincidence external chest scanning technique. The intravenous administration of not more than 50 μc of rubidium-84 in 30 cc of saline over a 30-minute period provides the necessary source of positron emitting isotope. The capillary, transcapillary, and transcellular migration of the isotope may be documented by external precordial coincidence counting. Thus, the myocardial blood flow